In residential and other structures, electrical outlets are generally positioned a short distance above the floor. This makes the outlets readily accessible to small children. A curious child is inclined to test and probe his environment and may stick objects, such as paper clips, into the prong receiving openings of an electrical outlet. This exposes him to the danger of shock or even death.
In spite of generally widespread knowledge of the dangers that electrical outlets present to small children, very few devices are commercially available for denying a child access to an outlet. The most commonly available device is a small plastic disk with prongs that plug into the openings of an outlet receptacle. The disk covers the receptacle and takes the place of an electrical plug to prevent insertion of any other object in the openings. A major disadvantage of this type of device is that the disk may easily become lost or mislaid when it is temporarily removed to allow normal use of the outlet.
There have been a number of proposals for providing a permanently mounted safety cover for electrical outlets to make the prong receiving openings inaccessible to a child. Such proposals generally provide an inadequate solution either because the safety cover is too easily defeated by a child who is still too young to understand the dangers of electricity or because the covering device is unduly complicated and/or cumbersome.
U.S. Pat. No. 3,068,442, granted Dec. 11, 1962, to J. T. Kubik et al., discloses a box-like cover that fits over a conventional outlet faceplate or has a back wall which forms a faceplate. Two sliding bars are mounted in the cover and are biased by coil springs into a position in which they cover the sockets of the outlet. A slide member is mounted in the cover and has a tab that projects upwardly from the top of the box. The tab may be pressed downwardly to cause the slide member to engage the bars and push them downwardly against the force of the springs to uncover the sockets.
U.S. Pat. Nos. 2,477,803, granted Aug. 2, 1949, to C. A. Huber, and 3,865,456, granted Feb. 11, 1975, to F. P. Dola, each disclose a cover plate for an electrical outlet which has slidable shutters for covering the prong receiving openings of the outlet sockets. The shutters have apertures extending therethrough for receiving the prongs of an electrical plug. The shutters are spring biased into a position in which the apertures are offset from the openings in the sockets, and may be moved into a position in which the apertures and openings are aligned by inserting the prongs of an electrical plug into the apertures and moving it against the force of the spring. The shutters in the Dola cover plate have beveled edges that slide in V-shaped guideways formed in the main body of the cover plate.
U.S. Pat. No. 2,710,382, granted June 7, 1955, to J. P. Fitzpatrick et al., also discloses a cover for an electrical outlet that has slidable apertured shutters. In one embodiment, the shutters are spring biased into an offset position, and in another embodiment gravity acts on the shutters to move them into an offset position. The cover includes a front or outer plate and a rear or inner plate. The inner plate has ridges that define the spaces in which the shutters reciprocate and provide guides for the movement of the shutters. In the spring biased embodiment, the springs are mounted in the spaces defined by the ridges. The rear surface of the inner plate has a pair of recesses for receiving the sockets of the outlet and a rearwardly projecting lateral lug that fits between the sockets.
U.S. Pat. No. 2,744,243, granted May 1, 1956, to G. H. Menendez, discloses a safety cover for an electrical outlet having apertured, gravity-actuated slides or shutters. The device includes a rear insulative plate and a front cover plate that defines recesses between itself and the insulative plate. The shutters reciprocate in the recesses. In one embodiment, each slide is tiltable in its recess and has lateral projections which engage depressions in the sides of the recess to prevent the shutter from being moved into its aligned position when it is tilted as opposed to being raised vertically. This arrangement is intended to prevent a child from aligning the shutter by inserting an object into one of the apertures and pushing on the shutter.
U.S. Pat. Nos. 4,168,104, granted Sept. 18, 1979, to D. W. Buschow, and 4,379,607, granted Apr. 12, 1983, to W. R. Bowden, Jr., each disclose an arrangement in which the openings of an electrical outlet are covered by shutters and which includes a mechanical mechanism for moving the shutters out of a blocking position. The Buschow device is operated by inserting the ground pin of an electrical plug into the device, and the Bowden, Jr. device is operated by inserting the two prongs of a plug simultaneously.
U.S. Pat. Nos. 2,559,151, granted July 3, 1951, to E. M. Getzoff, and 4,302,624, granted Nov. 24, 1981, to F. M. Newman, each disclose an electrical outlet protector having covers for the outlet sockets that pivot between open and closed positions. In the Newman device, spring biased shutters are pivotably attached to a main body. One embodiment includes a detent on the shutter that engages a recess in the body to provide resistance to opening of the device. In another embodiment, the shutter has a tab thereon which enters a recess in a center bar of the body when the shutter is closed. This prevents the shutter from being pried or lifted away from the socket, but allows the shutter to be pivoted into its open position.
U.S. Pat. Nos. 3,980,371, granted Sept. 14, 1976, to B. I. Kahn, 4,094,569, granted June 13, 1978, to E. W. Dietz, and 4,206,957, granted June 10, 1980, to M. S. Ludwig et al., each disclose a cube tap for an electrical extension cord having a spring biased apertured cover for the prong receiving openings. Safety covers for electrical outlets are disclosed by U.S. Pat. Nos. 2,934,591, granted Apr. 26, 1960, to V. V. Tiikkainen, and 3,201,740, granted Aug. 17, 1965, to G. J. Rubens. U.S. Pat. No. 4,159,858, granted July 3, 1979, to J. E. Toraya, discloses a cover plate for an electrical outlet having hinge mounted doors that cover the sockets and a magnetic lock to prevent the doors from being opened.
The above patents and the prior art that is discussed and/or cited therein should be studied for the purpose of putting the present invention into proper perspective relative to the prior art.